Question: $ { \left[\begin{array}{rrr}{4} & {0} & {2} \\ {0} & {4} & {1}\end{array}\right]+\left[\begin{array}{rrr}{3} & {-2} & {-1} \\ {1} & {4} & {1}\end{array}\right] = {?} } $
Answer: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rrr}{4}+{3} & {0}+{-2} & {2}+{-1} \\ {0}+{1} & {4}+{4} & {1}+{1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{7} & {-2} & {1} \\ {1} & {8} & {2}\end{array}\right]}$